Flame detector system



April24,1951' J.T. H|K 2,550,351

FLAME DETECTOR SYSTEM Filed Sept. 20, 1948 2 Sheets-Sheet 2 (Ittomeg Patented Apr. 24, 1951 UNITED STATES PATENT OFFICE V 2,550,351 a FLAME DETECTOR SYSTEM John Thomas Hick, MaIba, N. Y.

I Application September 20, 1948, Serial No. 50,089

Claims.

This invention relates to flame detectors.

n An object of this invention is to provide a flame detector or system which will detect the presence of flames at various spaced points, whereby to detect the spread of flame from one place to another. v

Another object of this invention is to provide a flame detector system comprising a plurality of flame detector units and signals normally in operative, and which will become operative when a flame contacts any on of the units, and means to put the unit which has been contacted by flame out of commission and to stop the signal from signalling so that should the flame contact another unit, the signal will again signal to indicate the spread of the flame.

Yet another object of this invention is to provide in a system of the character described, means to test the signal to see whether it is operative.

Yet a further object of this invention is to provide a strong, rugged and durable flame detector system of the character described, which shall be relatively inexpensive to manufacture, easy to manipulate, which shall be positive in operation, yet practical and efficient to a high degree in use. 7

Other objects of this invention will in part be obvious and in part hereinafter pointed out.

p The invention accordingly consists in the features of construction, combinations of elements, and arrangement of parts, which will be exemplifled in the construction hereinafter described,

and of which the scope of invention will be indicated in the following claims.

In. the accompanying drawings which is shown various illustrative embodiments of this invention,

Fig. l is a front view of one of the flame detector units embodying the invention, with the front cover removed;

Fig. 2 is a cross-sectional view taken on line 22 of Fig. l;

Fig. 3 is a cross-sectional view taken on line 3-3 of Fig. 2; I

Fig. 4 is a front view of one of the flame detector units embodying the invention, mounted on a support;

Fig. 5 is a cross-sectional view taken on line 44 of Fi 4;

Fig. 6 is an end view of one of said units;

Fig. '7 is a cross-sectional view taken on line 88 of Fig. 3; and

Fig. 8 is a wiring diagram illustrating a flame detector system mbodying the invention.

Referring now in detail to the drawings, i0 desi-gnates the wiring diagram for the flame detector system embodying the invention. The system [0 comprises a plurality of flame detector units II which may be placed in various parts of a compartment, room or building, enough units being employed to give adequate protection. Each unit H comprises a metal casing l2.

Each casing !2 comprises a semi-circular top wall i3 and end walls [4 extending therefrom. It has a bottom wall [5. The end walls It are formed with aligned through openings 10 adjacent the bottom wall l5. Said casing has side walls I! and Na and is formed with a circular through opening H3. The axis of the opening 13 is at right angles to the axis of the openings 16.

The side wall l'ia is formed with a substantially semi-circular flange IS. The flange I9 is formed with a plurality of screw threaded through openings 20.

The'to wall 13 is formed with 2. lug 22 having a through opening 23. The lug 22 extends across thewidth of the top wall. Said top wall is also formed with a lug 24 in alignment with the flange 19. The lug 24 is formed with a through opening 25; for the purpose hereinafter appearing. Extending down from the bottom wall [5 is a central lug 21 formed with a through opening 23 for the purpose hereinafter appearing. Extending from the end walls M are bosses 33 each formed at the top with a horizontal through opening 3|. Extending from the bosses 30 are externally screw threaded tubular projections 32. ,The through openings 16 pass through the bosses 36 as well as the'tubular extensions 32.

At one side of the semi-circular wall 13 is a lug 35 formed with a through opening 36 and disposed between the lug '26 and one end of the flange 59. At the opposite side of the wall I3 is a hook 3'! which may be ither integrally formed with the'top" wall, or may be attached thereto in any suitable manner.

Contacting'the inner su'rface'of the flange I9 is a semi-circular insulating plate 40. Plate 40 maybe attached to the flange l9 by means of screws M which pass through the threaded opening 20 in said flange. The top edge of the insulating plate 40 is horizontal and at the level of the ends of flange l9. Attached to the inner side of the insulating plate 40 is a metal plate 42. 'Screwedbnto said plate 42- is a binding post 43. Also fixed to said plate 42 is a spring clip 4i. Also attached to the insulating plate 40 is a second metal plate 45 spaced and insulated from the plate 42. P1ate45 is formed with an with the lug 35.

3 upstanding finger 41. Attached to the plate 45 is a spring clip 48. The finger 41 projects above the upper edge of the insulating plate 48.

Mounted on and between the spring clips 44 and 48 is a fuse 58 including a fuse element The terminals for the fuse element 5| are fixed to the spring clips 44, 48 and to the metal plates 42 and 45 by screws 52 and 53, or in any other suitable manner.

Fixed within the opening 25 in the lug 24 is a pin 55. Pivoted on the pin 55 is a lever 55 interconnected by a coil tension spring 51 to the opening 36 of the lug 35. The spring 51 interconnects an intermediate portion of the lever The lever 58 is also interconnected to the hook 31 by a thread or filament 60 made of inflammable material, that is, material which is more sensitive to flame than to heat. Nylon or silk thread may be employed for this purpose, also any element such as strips or filaments of metal, cotton, Wool, or plastic which will burn and break when contacted by flame.

It will be noted that the thread 60 retains spring 5'! under tension. At the outer end of lever 56 is a lug 58. If the thread 68 were to burn by contact with flame, and break, the spring 51 will swing the lever 58 in a clockwise direction, looking at Fig. 3, so that the lug 58 will strike the finger 41.

Attached to the sides of the casings 52 are cover members 62-. The cover members 82 are curved at the top and have a straight bottom edge 63, and the lower edges 84 at the sides are also straight, merging into the top curved edge 65. The cover members 62 are each formed in the upper half portions thereof with a plurality of slots or louvers 61. "The side walls l1, Ila of the casing are formed with through openings adjacent the bottom wall l5. The cover plates are attached to the casing by means of bolts H passing through the openings 23 and H1 of the casing. The flames may enter the casing through the louvers 61.

Each unit may be mounted on a support or bracket 14. The bracket 14 is attached to the casing by means of bolts passing through the openings 28 and 3| of the casing.

A plurality of said units II may be interconnected by means of flexible conduits 18, such as Brese cables. Attached to the ends of the conduits 18 are ferrules T! crimped onto the cable. Each ferrule has a flange 18 contacting one end of the externally screw threaded portion 32 and is clamped thereto by means of a screw coupling 19. The wiring which interconmeets the units passes through the conduits 16. The wiring diagram interconnecting the units 1 I will now be described.

Extending through the casings and through openings l6 thereof, and the cables 16, is a wire 88. The wire 88 goes back and forth through the casings and the cables or conduits. The wire 80 is connected by wires 8| to the binding posts 43 so that fuses 5| are connected in parallel with each other. It will be noted that the levers 58 are all grounded as at 82 due to their connections to the metal casings l3. The levers 56 as well as the pins '55 on which they are mounted are made of electric conducting material.

The wire 80. entering the first casing l2 passes through all the casings and the conduits interconnecting them, and then goes back, as shown in Fi 8 of the drawing. On any suitable bracket or support (not shown) ma be mounted an electric signal device 83, such as a lam or bell, having terminals 84 and 85. The wire 88 has terminals 88a and 881) which may be mounted on the support or bracket on which the signal 83 is mounted. The terminal 85 is connected by wire 86 to the terminal a of the wire 86. The other terminal 84 is connected through wire 8! to one side of a battery or other source of electric power 88, the other side of which is grounded as at 89. Onthe support on which the signal 83 is mounted, is a push button switch 98 adapted to interconnect a pair of terminals 8! and 92. The terminal 92 is connected to the terminal by wire 94. The terminal 9! is connected to the terminal 84 by wire 95. ie push button 98 is normally open. When it is closed, the signal 83 is short circuited.

Terminal 88a is connected by wire 96 to a contact 9?. Attached to the terminal 801) is a manual switch arm 98 adapted to contact the terminal 9? in one position of the switch. Said switch 98 is adapted to swing into engagement with a second contact 98 grounded as at I08.

The operation of the flame detector system embodying the invention will now be described. The various units H are placed at spaced points of an airplane engine cowling or at spaced points of any compartment, room, or on any apparatus wherever it is desired. Normally the test switch 88 is closed, that is, it engages the contact 9? and the push button switch 98 is open. In such condition the signal 83 will not be energized. However, if the switch 98 is moved into engagement with the Contact 98, the circuit will be completed to the signal 88 through ground 89, battery 88, wire 8'3, signal 83, wire 86, wire 89, switch 98, contact 98 and ground I80.

When the operativeness oi the signal has been tested and assured, the switch is again moved into engagement with the contact 8? and the signal will not be energized. However, should the filament or thread 88 of any unit be contacted by flame passing into the casing through louvers 8?, the thread will burn and break and the spring 5'! for that unit will swing lever 56 to cause the lug 58 to engage the finger 41, thus closing the circuit through the signal device 83 and the fuse 5| for that unit. The circuit is through ground 89, battery 88, wire Bl, signal 88, wire 86, wire 81L wire 8|, fuse 5|, finger 41, lug 58, lever 55 and ground 82.

When the signal is energized, the operator may cause CO2 gas to enter the place where the units are located to extinguish the flame, or any other suitable flame or fire extinguishing method may be used. After steps are taken to extinguish the flame, the operator may close the normally open switch 98, causing the signal 83 to be short circuited and imposing full voltage on the fuse 5| in the unit with the broken thread 88. The fuse will blow. The push button is then released and again opens, and the circuit through the signal is then broken and said signal will again be deenergized. If, thereafter, the flame reaches the thread of another unit and the thread burns and breaks, the signal will again be energized and the operator will know that the flame is spreading and will again apply the flame extinguishing steps.

If the signal does not again become energized, it will indicate to the operator that the flame is not spreading. After one fuse is blown the signal device may be tested by means of test switch 93. It will now be understood that with the blowing of a fuse the unit which was in the fire area will be put out of commission, allowing the other detector units to be operative.

It will thus be seen that there is provided a device in which the several objects of this invention are achieved and which is well adapted to meet the conditions of practical use.

As various possible embodiments might be made of the above invention, and as various changes might be made in the embodiment above set forth, it is to be understood that all matter 1 herein set forth or shown in the accompanying drawings is to be interpreted as illustrative and not in a limiting sense.

It will now be understood that with the present system there will be no false alarm due to heat alone and when the signal actuates youcan be sure that there is flame and hence fire.

Having thus described my invention, what I claim as new and desire to protect by Letters Patent of the United States is:

1. A flame detector system comprising a plurality of fiame detector units, each unit comprising a contact, a fuse in series circuit with each contact, an electric signal device, means to connect said fuses in parallel with each other and each in series with said signal device, each unit including a movable contact, means to urge the movable contact of each unit into engagement with the first contact of said unit, means to retain the movable contact of each unit out of engagement with the first contact of said unit, said last means including a filament adapted to break upon burning by contact with flame to permit the urging means for said unit to move the movable contact into engagement with the first contact for completing the circuit to the electric signal device for energizing the same, and means to short circuit the electric signal device, each fuse being of such rating that it will blow when the signal device is short-circuited,

and will not blow when the signal device is included in its circuit.

2. A flame detector system comprising a plurality of flame detector units, each unit comprising a fixed contact, a fuse in series circuit with each contact, an electric signal device, means to connect said fuses in parallel with each other and each in series with said signal device through common wiring, each unit including a movable contact, spring means to urge the movable contact of each unit into engagement with the fixed contact of said unit, means to retain the movable contact of each unit out of engagement with the fixed contact of said unit, said last means including a, filament adapted to break upon burning by contact with flame to permit the spring means for said unit to move the movable contact into engagement with the fixed contact for completing the circuit to the electric signal device for energizing the same, each fuse being of such rating that it will blow when the signal device is short-circuited and will not blow when the signal device is included in its circuit, manual switch controlled means to short circuit the electric signal device, a second manual switch, means controlled by said last switch to energize said signal at will, to test the operativeness of said signal device and said common wiring, a casing for each unit, conduit means interconnecting said casings, and the wiring which interconnects said fuses and signal passing through said conduits.

3. A flame detector system comprising a plurality of flame detector units, each unit including a filament which will burn by contact with flame, an electric signal, and means to actuate said signal when any of the filaments burn and break, said means including a fuse for each unit, means to connect said fuses in parallel circuit with each other and in series circuit with said signal, and means controlled by the breaking of each filament to complete the circuit for the fuse of the unit for said filament and the signal, and manual means to short circuit said signal, each fuse being of such rating that it will blow when the signal device is short-circuited, and will not blow when the signal device is included in its circuit.

4. A flame detector system comprising a plurality of flame detector units, each unit including a filament which will burn by contact with flame, an electric signal, and means toactuate said signal when any of the filaments burn and break, said means including a fuse for each unit, means to connect said fuses in parallel circuit with each other and in series circuit with said signal through common wiring, and means controlled by the breaking of each filament to complete the circuit for the fuse of the unit for said filament and the signal, and manual means to short circuit said signal, each fuse being of such rating that it will blow when the signal is shortcircuited, and will not blow when the signal is in its circuit, and manual means to energize said signal and wiring at will.

5. A fiame detector system comprising a plurality of flame detector units, each unit comprising a contact, a fuse in series circuit with each contact, an electric signal device, means to connect said fuses in parallel with each other and each in series with said signal device through a common wire, each unit including a movable contact, means to urge the movable contact of each unit into engagement with the first contact of said unit, means to retain the movable contact of each unit out of engagement with the first contact of said unit, said last means including a filament adapted to break upon burning by contact with flame to permit the urging means for said unit to move the movable contact into engagement with the first contact for completing the circuit to the electric signal device for energizing the same, each fuse being of such rating that it will blow when the signal device is shortcircuited and will not blow when the signal device is included in its circuit, means to short circuit the electric signal device, a manual switch, and means controlled by said switch to energize said signal at will, to test the operativeness of said signal through said common wire.

JOHN THOMAS HICK.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 581,544 Enholm Apr. 27, 1897 1,068,440 McCarthy July 29, 1913 1,961,578 Bowers June 5, 1934 2,000,185 McBrien May '7, 1935 2,127,343 Parlett Aug. 16, 1938 2,220,371 Hopkins Nov. 5, 1940 2,469,501 Gogniat May 10, 1949 FOREIGN PATENTS Number Country Date 555,268 Great Britain Aug. 13, 1943 643,198 Germany May 4, 193'], 

